Resonators can be used as a passive component of a filter in the radio transmission link. In practice filters almost always consist of several coupled resonators. As the signal frequency of the signal transmission on a radio link increases, the requirements of the filter change, in particular the structural and spatial requirements, as well as the requirements for the usable bandwidth of a filter changes. The usable bandwidth is that frequency bandwidth in which a filter response to a central frequency is constant or nearly constant.
Typically, such filters are designed as self-compensating components of a higher order and are for example used in input multiplexers (IMUX).